Bug 296383: during startup, check that resources calendar opens ok

[KResources build option]: Prevent crash in program initialisation by
checking that the resources calendar has opened successfully.

BUG:296383

alarmcalendar.cpp

@@ -223,12 +223,27 @@ AlarmCalendar::~AlarmCalendar()
     close();
 }
 
+/******************************************************************************
+* Check whether the calendar is open.
+*/
+bool AlarmCalendar::isOpen()
+{
+#ifndef USE_AKONADI
+    if (mOpen  &&  mCalType == RESOURCES  &&  !AlarmResources::instance())
+    {
+        mCalendar = 0;
+        mOpen = false;
+    }
+#endif
+    return mOpen;
+}
+
 /******************************************************************************
 * Open the calendar if not already open, and load it into memory.
 */
 bool AlarmCalendar::open()
 {
-    if (mOpen)
+    if (isOpen())
         return true;
     if (mCalType == RESOURCES)
     {
@@ -287,7 +302,7 @@ bool AlarmCalendar::open()
         mCalendar = 0;
 #endif
     }
-    return mOpen;
+    return isOpen();
 }
 
 /******************************************************************************

alarmcalendar.h

@@ -120,7 +120,7 @@ class AlarmCalendar : public QObject
         bool                  deleteEvent(const QString& eventID, bool save = false);
 #endif
         void                  purgeEvents(const KAEvent::List&);
-        bool                  isOpen() const         { return mOpen; }
+        bool                  isOpen();
         QString               path() const           { return (mCalType == RESOURCES) ? QString() : mUrl.prettyUrl(); }
         QString               urlString() const      { return (mCalType == RESOURCES) ? QString() : mUrl.url(); }
         void                  adjustStartOfDay();

kalarmapp.cpp

@@ -2229,7 +2229,8 @@ bool KAlarmApp::initCheck(bool calendarOnly)
          */
         AlarmCalendar::displayCalendar()->open();
 
-        AlarmCalendar::resources()->open();
+        if (!AlarmCalendar::resources()->open())
+            return false;
         setArchivePurgeDays();
 
         firstTime = false;